Publication Date:
2024-01-09
Description:
The changing composition of radiolarian faunas from late Neogene deep-sea sediments has been used in recent years as a proxy for changes in marine paleoproductivity. We examine radiolarian faunas, organic carbon content (TOC), opal and coarse-fraction components over the last 270,000 years in sediments from ODP Hole 1084A, drilled in a high productivity upwelling region within the Benguela Upwelling System off the west coast of Africa. Age control is provided by stable oxygen isotope measurements of benthic foraminifera. Prior research has established that late Pleistocene glacial intervals in this upwelling system generally had higher productivity than interglacials. The radiolarian WADE (water-depth ecology) paleoproductivity index correlates well with TOC and opal in these samples, and all three parameters change in synchrony with the benthic isotope curve over all but the MIS 5e–6 time interval. WADE inferred productivity is significantly higher in glacials than interglacials. We conclude that the WADE index is a useful proxy for paleoproductivity at this location, as are also opal and organic carbon accumulation rates. Carbonate and carbonate based indices such as the accumulation rate of benthic foraminifera (BFAR) by contrast do not correlate well either to productivity indices or to the glacial–interglacial cycle, and are interpreted to primarily reflect carbonate dissolution.
Keywords:
175-1084A; Acanthosphaera corlocae; Accumulation rate, benthic foraminifera by number; Accumulation rate, mass; Acrosphaera murrayana; Actinomma antarcticum; Actinomma boreale; Actinomma leptodermum; Actinomma popofskii; AGE; Amphirhopalum ypsilon; Antarctissa spp.; Anthocyrtidium ophirense; Anthocyrtidium zanguebaricum; Arachnocorys circumtexta; Benguela Current, South Atlantic Ocean; Botryocyrtis scutum; Botryostrobus aquilonaris; Botryostrobus auritus/australis; Calcium carbonate; Calculated; Carbon, organic, total; Carpocaniidae indeterminata; Cladococcus sp.; Cornutella profunda; Counting 〉150 µm fraction; Counting 〉45 µm fraction; Cycladophora bicornis; Cycladophora conica; Cycladophora davisiana; Cyrtopera laguncula; DEPTH, sediment/rock; Dictiocoryne profunda; Dictyophimus crisiae; Dictyophimus infabricatus; Didymocyrtis tetrathalamus; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Element analyser CHNS-O; Eucyrtidium acuminatum; Eucyrtidium calvertense; Eucyrtidium teuscheri group; Heliodiscus asteriscus; Helotholus histricosa; Joides Resolution; Lamprocyclas maritalis; Lamprocyrtis heteroporos; Lamprocyrtis nigriniae; Larcopyle buetschlii; Leg175; Lipmanella dictyoceras; Lithelius minor; Lithomelissa hystrix; Lithomelissa setosa; Lithostrobus hexagonalis; Lophospyris pentagona; Mass spectrometer GV Instruments Isoprime; Ocean Drilling Program; Octopyle stenozona; ODP; Ommatodiscus irregularis; Opal, biogenic silica; Opal, extraction; Mortlock & Froelich, 1989; Peripyramis circumtexta; Phelodinium cranwelliae; Phormospyris stabilis stabilis; Phormostichoartus corbula; Phormostichoartus pitomorphus group; Plectacantha cresmastoplegma; Primary production of carbon; Prunopyle antarctica; Pseudodictyophimus gracilipes; Pterocanium auritum; Pterocanium hirundo group; Pterocanium praetextum praetextum; Pterocanium trilobum; Pterocorys minythorax; Pterocorys zancleus; Radiolarians; Radiolarians, intermediate/radiolarians, warm ratio; Radiolarians, intermediate water depth; Radiolarians, other; Radiolarians, temperate; Radiolarians, upwelling; Radiolarians, warm; Saccospyris antarctica; Sample code/label; Siphocampe arachnea; Spirocyrtis spp.; Spongocore cylindrica; Spongopyle osculosa group; Spongotrochus venustum; Stichocorys peregrina; Theocorys veneris; Theocorythium trachelium; Uvigerina spp.; Uvigerina spp., δ18O; Zygocircus spp.
Type:
Dataset
Format:
text/tab-separated-values, 2976 data points
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